Rolling-mill apparatus



Nov. 13, 1923.

F. MAYER ROLLING MILL APPARATUS Filed Aug. 12. 1921 Patented Nov. l3, i923.

FRIEDRICH IMAYER, OF MUNICH, GERMANY.

ROLLING-MILL APPARATUS.

Application filed August 12, 1921. Serial No; 491,753.

To all whom it may concern.

Be it known that I, Fnrnninorr MAYER, a citizen of Germany, and resident of Munich, Germany, have invented certain new and useful Improvements in ltollingdllill Apparatus (for which I have filed an application in Geinany, Mar. 28, 1918, Serial No. M 62,896), of which the following is a specilication.

The invention relates to rolling mills, and more especially to a method of, and apparatus for, feeding the piece to be rolled.

The methods hitherto employed do not allow, despite the complicated devices heretofore installed, of the feed motion being adjusted easily and within wide limits, as'it has been found necessary during the rolling process and when changing the rolling speed .or the weight of the hollow blooms rolled.

It is the object of the invention to obviate the objectionable features present in the known types and to effect the operation of rolling in as simple a manner as possible, while assuring safety in operation and reduction of the mass of the reciprocating members to a minimum.

To this end, the mandrel, on which the pierced bloom is rolled down, is coupled with a piston capable of reciprocation within an airtight cylinder, in accordance with the rolling process and the feed motion. The cylinder is provided at both ends with an air or, preferably, with air ports which are adapted to be closed by the piston just'before it reaches the extreme positions of its travel, so that the motion thereof is stopped quickly and without shock at the end of the piston stroke and the acceleration of those parts of the machinery which move forwardly and backwardly during the rolling operation is effected energetically in the opposite direction. furthest from the rolling mill is fed with compressed air at high pressure, as well as the near air port or port placed nearest the mill, but at a somewhat lower pressure, so that the difference of pressure supplies the energy for feeding the work. The alteration in the compressed air pressures in front of and behind the piston gives then a very suitable and accurately acting medium to control the whole feed motion, as desired. Generally, it will suffice to alter only the pressure of the compressed air destined for the near air port and to alter the pressure of the compressed air for the far cylinder space highly compressed air.

The far air port or port only when changing the rolling program. By the use of high pressure air on both sides of the piston, considerable braking force will be obtained even with small piston diameters, as soon as the piston covers the respective air ports and continues to compress the already As, according to the new method, the pressure of the compressed air on one side of the piston can be altered quite independently of that on the other side of the piston, one is able easily and conveniently to adjust the feed and brake forces independently of each other and within considerable limits. In practice, it will in most cases be found best, for the sake of simplicity, to take the compressed air for the anterior cylinder space from the compressed air piping of the rear cylinder space as inintroducing suitable, regulatable reducing valves, so that only one compressed air plant is required.

The accompanying drawing shows one form of apparatus in which the invention is embodied.

Referring to the drawing, a mandrel is shown coupled within a twist bar (6) and the latter with the piston rod (0) and piston ((11). The piston (d) is reciprocable in an airtight cylinder (0), its rod (0) passing thru a stuffing box (f) and is brought near the rolling mill by the aid of well-known feeding devices (not shown) in accordance with the progressing rolling process. A plurality of ports (g), are provided at the near end of the cylinder for the purpose of regulating the beginning of compression and are connected with the compressed air feed pipe by means of regulating valves (h), compressed air of, for e ample. i atmospheres being fed to one side of the piston. lVhereas, there is fed on the other side of the piston thru the ports (is) which are like wise connected with a source of compressed air as the feed pipe thru regulating valves (Z), compressed air of a higher pres sure, for example at 6 atmospheres.

If the piston (d) is moved in cylinder (6) in the direction of the arrow 1, while the rolling takes place in the direction of the arrows 3, the pressure in the far cylinder space amounts, in the first instance, to approximately 6 atmospheres and about 4 atmospheres in the near cylinder space until toward the end of the stroke to the right, the piston being moved in the direction of arrow (1) under the force exerted by the rolls upon the bloom while rolling same. The valves (1) are kept open during this rolling action, in order that the pressure of 6 atmospheres will not'be increased. The piston (d) then covers progressively the ports (is), thereby causing a rapid increase of pressure behind the piston, by which the run-out passage of the rolled piece after leaving the rolls is limited to a small distance which also i regulatable by adjusting the valves (Z) 5 and to the piston, piston rod, twist bar, mandrel and piece to be rolled may then give an effective acceleration'in the directionof the feed motion, indicated by the arrow 2. While moving further in the direction of the arrow 2, the ports (is) are again opened, the piston then being under a constant pressure of 6 atmospheres, and overcoming the pressure of 4 atmosphere on the other side at which the compressed air flows off thru the ports (9). Towards the end of the feed motion, the piston (fl) covers the ports (g), whereby the sudden increase of pressure, which can also be regulated by the adjustment of the valves (it), quickly stops the feed motion and initiates without shock the movement in the direction for rolling-direction indicated by arrow 1..

The braking of the feed motion is not only governed by adjusting the valves (h) but, according to the present invention, one may influence the feed and braking forces with in large limits by changing the pressure in the compressed air piping and the piping (m). After having determined the proper adjustment f the pressures for certain rolling speeds and hollow bloom weights during the rolling process, the pressures can be maintained constant in both compressed air pipings. Safety valves (n) and (0)- are provided at each end of the cylinder to prevent excessive pressures.

I claim:-

1. In rollin mills: the method of reciprocating the piece to be rolled, thru the operation of compressed air, which consists in maintaining air under pressure upon both sides of a movable piston connected with the piece, and regulating the pressures thereof independently of each other.

2. In rolling mills: the method of reciprocating the piece to be rolled, thru the operation of compressed air, which consists in maintaining air under pressure upon both sides of a movable piston connected with the piece, and maintaining continually a greater pressure of air at one side of the movable piston.

3. Apparatus for use with rolling mills,

pressure of the air supplied upon opposite sides of the piston.

Apparatus for use with rolling mills, comprising an airtight cylinder and piston reciprocable therein under compressed air supplied t both sides thereof, said piston being connected with the piece to be rolled,

and said cylinder being provided with a plurality of ports at each end to be closed progressively by the piston; and regulating valves to control the pressure of the air supplied thru the individual ports.

6. Apparatus for use with rolling mills, comprising anairtight cylinder and piston reciprocable therein under compressed air supplied to both sides thereof, said piston being connected with the piece to be rolled, and said cylinder being provided with a plurality of ports at each end to be closed progressively by the piston: regulating valves to control the pressure of the air supplied thru the individual ports; and safety valves at each end of the cylinder.

Signed at Munich in the county of Bavaria and State of Germany this twentieth day of July A. D. 1921.

FRIEDRICH MAYER. 

